/*
*    Qizx/open 3.0 beta
*
* This code is the open-source version of Qizx.
* Copyright (C) 2004-2009 Axyana Software -- All rights reserved.
*
* The contents of this file are subject to the Mozilla Public License 
*  Version 1.1 (the "License"); you may not use this file except in 
*  compliance with the License. You may obtain a copy of the License at
*  http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
*  WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
*  for the specific language governing rights and limitations under the
*  License.
*
* The Initial Developer of the Original Code is Xavier Franc - Axyana Software.
*
*/
using System;
using EvaluationException = System.Qizx.Api.EvaluationException;
using EvalContext = System.Qizx.XQuery.EvalContext;
using ExprDisplay = System.Qizx.XQuery.ExprDisplay;
using Focus = System.Qizx.XQuery.Focus;
using ModuleContext = System.Qizx.XQuery.ModuleContext;
using XQType = System.Qizx.XQuery.XQType;
namespace System.Qizx.XQuery.Op
{
	
	/// <summary> class QuantifiedExpr:</summary>
	public class QuantifiedExpr:BooleanExpression
	{
		
		public bool every;
		
		public Expression cond;
		
		protected internal Expression[] varClauses = new Expression[0];
		
		public QuantifiedExpr(bool every)
		{
			this.every = every;
		}
		
		public virtual void  addVarClause(Expression varClause)
		{
			varClauses = addExpr(varClauses, varClause);
		}
		
		internal virtual Expression getVarClause(int rank)
		{
			return rank < 0 || rank >= varClauses.Length?null:varClauses[rank];
		}
		
		public override Expression Child(int rank)
		{
			return (rank < varClauses.Length)?varClauses[rank]:(rank == varClauses.Length?cond:null);
		}
		
		public override void  Dump(ExprDisplay d)
		{
			d.header(this);
			d.property("every", "" + every);
			d.children("varClauses", varClauses);
			d.child("cond", cond);
		}
		
		public override Expression StaticCheck(ModuleContext context, int flags)
		{
			LocalVariable mark = context.latestLocalVariable();
			for (int c = 0; c < varClauses.Length; c++)
				context.staticCheck(getVarClause(c), 0);
			cond = context.staticCheck(cond, 0);
			type = XQType.BOOLEAN; // no check: effective bool value
			context.popLocalVariables(mark);
			return this;
		}
		
		public override bool evalAsBoolean(Focus focus, EvalContext context)
		{
			// dummy iterator as init stub:
			VarClause.SingleDummy source = new VarClause.SingleDummy(focus, context);
			for (int c = 0; c < varClauses.Length; c++)
			{
				VarClause.SingleDummy newSrc = (VarClause.SingleDummy) getVarClause(c).eval(focus, context);
				newSrc.Source = source;
				source = newSrc;
			}
			if (every)
				for (; ; )
				{
					if (!source.Next())
						return true;
					if (!cond.evalEffectiveBooleanValue(focus, context))
						return false;
				}
			else
				for (; ; )
				{
					if (!source.Next())
						return false;
					if (cond.evalEffectiveBooleanValue(focus, context))
						return true;
				}
		}
	}
}